Seat Belt Bolts

[Guest paul mercer]

I went to my local 'stores' to see what seat belt bolts they had. I was surprised when i was presented with a selection of m10 bolts. I was under the impression that seat belt bolts were imperial. The m10 bolts are all standard parts on new ford cars so must be legal.

 

Can anyone confirm that this is ok for sva now?

 

paul

[Guest Battery Bill]

Paul

The SVA bible says the bolts must be at least 11 mm or 7/16" and of grade 8.8 or higher.

It also says the grade may not be shown on the bolts produced for seat belt anchorages

Finally it says "other bolt fixings may be acceptable if they are deemed to be of equivalent strength"

So there you go clear as mud

We are using M12 bolts which fit nicely and are 8.8 strength

[Guest Ianz]

Bill

 

You may be right as to what the bible says ......but

The SVA bible says the bolts must be at least 11 mm or 7/16" and of grade 8.8 or higher.

It also says the grade may not be shown on the bolts produced for seat belt anchorages

 

A seat belt bolt is a specific kind ,I believe its 7/16 UNF, ie a fine thread,

the head of the bolt is quite distinctive,flatter than a usual bolt,and has chamfered

corners.

INMHO I believe that SVA testers like to see these fitted,along with

matching captivated nuts....welded to the seat belt bracket.

 

Paul

Try and get the correct bolt,if you have trouble let me know as I have a

good motor factors who stocks these bolts,I could get them for you,for cost

plus postage.

 

You know it makes sense

 

Cheers all Ian

[Guest Mr Pid]

This may sound like a very silly question BUT:

 

After redoing my seats and frames about ten times trying to get them to comply with the SVA requirements i thought i better ask it before i end up knocking the bloke out at the SVA centre when the goal posts get widened yet again. :gdit:

 

the Bolts for the seat belts you say have to be M10 or M12 etc, but what does this mean. I do have a slight clue as i am thinking it corresponds the the strength and the size of the hole you have to drill in which the bolt will pass through. Mine are currently at 10mm big, but the seats are still out (cos im lazy-luckily) so it would be easy to rectify this before they go back in otherwise there will be more red mist on the horizon. :boohoo:

 

Othe car manufacturers i know have much smaller bolts than these, i seem to remember some belt fixings were actually held on by a couple of big rivets!!!

 

any clarrificatio would be much appreciated.

 

Cheers

 

Stu

[Guest gordon_macnab]

The "M" part refers to a metric thread and the 10/12 etc refers to the bolt diameter in mm. Other bolt types eg 7/16" UNF refer to a UNF type thread with a bolt diameter of 7/16".

 

8.8 is a specifc grade of bolt material that has a specific tensile strength, the higher the number the stronger ther bolt.

 

Gordon

[Guest Ianz]

Stu

Read my previous post.

 

As I said, seat belt bolts ARE VERY DISTINCTIVE,

Ignore what volume car makers do,I have looked at a number of cars and

wondered whether they would get through an SVA test...I think not.

 

For the sake of a couple of quid get the right bolts,also look very carefully

at the structure to which the seat belt bolts are mounted too,as from what

I've read this is one area which is a favorite for examiners to be picky.

 

Cheers Ian

[Guest Mr Pid]

Ahh Ian you must have posted that while i was furiously typing my post.

 

I guess the logical follow on from this is what about the seat frame bolts?

 

I guess these are not too important as so long as the belts keep you in the seats are a secondary feature.

 

Mine are currently 10mm on sturdy frames made from 5mm thick steel.

 

I do remember Richard having a big arguement which involed quoting all sorts of european legislation regarding the rear belt bolts behind the seats. Apparently if you are using harnesses the SVA people dont like these?!? Not strong enough they reckon even though they are welded on.

 

Any ideas?

 

Stu

[Guest Ianz]

Stu

Firstly a piccy of a pucker bolt

[Guest Ianz]

Stu.......

and another one!!!

I'm going to find what it says in the SVA manual about seat belts and mountings

and hopefully clarify things a tad

Ian

[Guest Ianz]

Stu

 

Unfortunately I have been unable to get my scanner going!!!!!!!

As I was hoping to scan the relevant pages from the SVA manual,

but basically the situation is that in the manual the seat mounting regs is 1 page,they check that generally the structure is sound,

on the other hand seat belt mountings account for 15 pages of the SVA manual,they say that in the event of a heavy front end collision the seat belts and mounts need to withstand a pressure of 1.5 tons!!!!!

So it appears that the emphasis is on the seat belts and mountings,

not the seats.

So back to first point........get proper seat belt bolts.....they are referred to as such.

 

Cheers Ian

[Guest daveg]

piccy of a pucker bolt

that not a bolt...its a set screw!

 

On my 2b....I used 12mm bolts on the rear and 12mm set screws to the chassis (RH even drilled the hole already) and seat frame (home made)

 

Dave

[Guest Battery Bill]

Ianz

Whats the point in having the seats mounted increadibly strongly ?

If your seatbelts are mounted securely the bloody seats going nowhere

 

The shoulder harness of the 2b is bolted to tubes "behind" the box section chassis member and this ideal is as the sva book mentions "upper anchorage must be adequately braced to strong areas of the chassis.

 

There is nowhere in the book that tells you to use a certain type of thread

An M12 with stiff nuts is as the manual says "Acceptable"

 

You tell me what is going to break first in an accident, the M12 or your neck

 

 

Stu

 

I do remember Richard having a big arguement which involed quoting all sorts of european legislation regarding the rear belt bolts behind the seats. Apparently if you are using harnesses the SVA people dont like these?!? Not strong enough they reckon even though they are welded on.

 

I think the problem here was that the tubes that held the bolts were welded on the front of the chassis member, that is why they are now on the rear side of the member.

[Guest jetskijase]

Hi People

 

Bill

 

I think the problem here was that the tubes that held the bolts were welded on the front of the chassis member, that is why they are now on the rear side of the member.

 

Is this true?? anyone??

 

I have heard of people having trouble at the sva because of these mountings, i didnt realise that they were on the front of the box section.

 

I get the idea that with regards the bottom mounts that the more over the top you go the better.

 

Jase

[Guest Ianz]

Daveq

 

When was your car SVA'D????????

On my 2b....I used 12mm bolts on the rear and 12mm set screws to the chassis (RH even drilled the hole already) and seat frame (home made)

 

 

Bill

 

You should actually read what i said properly,not go off half cocked as you usually do

Whats the point in having the seats mounted increadibly strongly ?

If your seatbelts are mounted securely the bloody seats going nowhere

 

I said

but basically the situation is that in the manual the seat mounting regs is 1 page,they check that generally the structure is sound,

And I have now included the section of the manual which describes the bolts.

Bill,by the way when did your car pass its SVA then ??????????????probably same time as DaveQ

[Guest Ianz]

Here it is